An intraluminal prosthesis is a medical device used in the treatment of diseased bodily lumens. One type of intraluminal prosthesis used in the repair and/or treatment of diseases in various body vessels is a stent. A stent is a generally longitudinal tubular device formed of biocompatible material which is useful to open and support various lumens in the body. For example, stents may be used in the vascular system, urogenital tract, gastrointestinal tract, esophageal tract, tracheal/bronchial tubes and bile duct, as well as in a variety of other applications in the body.
Stents generally include an open flexible configuration. This configuration allows the stent to be inserted through curved body lumens. Furthermore, this configuration allows the stent to be configured in a radially compressed state for intraluminal delivery. Once properly positioned adjacent the target location in the body lumen, the stent is radially expanded so as to support and reinforce the body lumen. Radial expansion of the stent may be accomplished by inflation of a balloon attached to the delivery device or the stent may be of the self-expanding variety which will automatically radially expand once unconstrained by the delivery device.
Various techniques or systems have been proposed for retrieving and/or repositioning an implanted stent. For example, some stents may include a retrieval suture or wire located at one end of the stent. The retrieval suture or wire may be engaged by a retrieval tool, and, upon twisting or axially pulling retrieval suture or wire, the stent is contracted thereby allowing retrieval of the stent.
Prior retrieval systems often require certain user-sensitive techniques, such as twisting or turning in order to reposition or remove the stent. Moreover, the retrieval suture or wire that allows the stent to purse down or reduce in diameter generally results in a reduction in diameter over a relatively short distance from the end of the stent that the retrieval suture or wire is located and does not cause the stent to be reduced in diameter along a majority of the length of the stent. The removal of the stent is then reliant on an extraction force sufficient to overcome the frictional resistance between the stent and the intimal wall of the body lumen.
Accordingly, there is an ongoing need to provide alternative repositioning and/or retrieval mechanisms for an intraluminal prosthesis, such as a stent.